A liquid crystal display (LCD) device is one of flat panel display devices that are currently used a lot. An LCD device includes electric field generating electrodes and a liquid crystal layer, and generates an electric field on the liquid crystal layer by applying a voltage to the electric field generating electrodes, thereby determining the direction of liquid crystal molecules of the liquid crystal layer and adjusting the transmittance of light that passes through the liquid crystal layer.
In order to display colors, an LCD device includes color filters. The color filters may include red, green, and blue filters and may be formed on every pixel to display colors by controlling the intensity of light that passes through each pixel. Colors may be combined to display full colors.
Color filters may be formed by using a lithography process including coating, exposing, and developing processes, or an inkjet printing method for injecting liquid ink onto predetermined regions defined by barriers. However, color filters may require high costs and may reduce light transmittance.
Currently, research is being conducted on methods of displaying colors without using color filters. One of those methods is a method using cholesteric liquid crystals. Since cholesteric liquid crystals have liquid crystal molecules that are oriented in a helical structure and reflects light of a certain wavelength according to a pitch of the helical structure, predetermined colors may be displayed by adjusting the pitch.
However, since cholesteric liquid crystals exist in a fluid phase, in order to allow the cholesteric liquid crystals to have different pitches between different pixels, red, green, and blue panels should be independently formed and stacked, or an additional structure for separating the cholesteric liquid crystals is required. In this case, processes may be complicated, manufacturing costs may be increased, and the resolution of a panel may be restrictive.